November 10, 2013
Researchers at Georgia Tech have developed a new technique to print advanced, ink-based electrical circuitry on a desktop printer. Using about US$300 worth of off-the-shelf equipment, the researchers were able to print arbitrary-shaped circuits on resin-coated paper, PET film, and glossy photo paper with silver nanoparticle ink.
Printing circuits isn’t entirely new, but the team’s technique makes the process faster and cheaper. Similar to graphene-based printing done at the Max Planck Institute, Georgia Tech’s method uses empty ink jet cartridges, except it does not require heating for ink placement.
Initiated by the University of Tokyo and with Microsoft Research contributing to the concept, Georgia Tech took the reigns of the project building on its materials and circuit design expertise previously seen in the creation of paper-based sensors for explosives. The team was able to print ink-based circuits in as little as 60 seconds.
“We believe there is an opportunity to introduce a new approach to the rapid prototyping of fully custom-printed circuits,” says Gregory Abowd, Regents’ Professor in Georgia Tech’s School of Interactive Computing. “The tools needed to create electronic circuitry are now at the point where anyone can afford to experiment. This is probably more true with professionals at the moment than it is for everyday consumers.”
Abowd told us he believes the research will directly impact professionals and university researchers who want to experiment with novel forms of interactive electronics. “As one of my students, Aman Parnami, explained, this is part of the beginning of an era of personal fabrication,” he said. Yoshihiro Kawahara from the University of Tokyo added, “Even for professional electrical engineers, the emergence of the new chemical sintering (virtually sintering free) ink is big news.”
The technique is meant to be accessible to makers and DIYers, as well. “Ink cost is $200 per a bottle (100 ml), the printer is about $80, and empty cartridges are $10 or so,” Kawahara explains. A bottle of the ink, available from Mitsubishi Imaging, covers more than 10 m2, which the researchers say is as good as particle-free silver ink, which requires more complex machinery to get the ink on paper. The technique is not compatible with canvas cloths and magnet sheets.
The printed circuits can be attached to electrical designs and components using conductive double-sided tape or silver epoxy adhesive. The researchers demonstrated the quality of their printed circuit by attaching a capacitive ribbon containing their inkjet-printed circuits to a glass. After connecting the contoured circuitry to a micro-controller, they were able to measure the liquid contents of the glass.
The fabrication techniques are explained in a paper published by the researchers, and all of the supplies are off-the-shelf.